الفهرس | Only 14 pages are availabe for public view |
Abstract Ferrite grain-refinement is a promising approach to improve both the strength and the toughness of steels simultaneously. Among recent ferrite refinement techniques, dynamic strain induced transformation (DSIT) is applied. In this work, a framework consisting of 24 plant scale trials (160 tons each) was performed in the compact strip production (CSP) plant at EZDK company. Micro-alloying with Nb (0.002, 0.022, 0.032 and 0.042 wt%) along with designing the hot rolling parameters (strain, hot deformation temperature at each of six rolling stands and the coiling temperature) were used to produce the required microstructure and properties. The effect of change both Nb content and rolling parameters on grain refining, mechanical properties and formability of hot rolled low carbon steel were linked and studied. Stress induced grain refinement has been successfully achieved, aided by Nb, resulting in an average grain size of 3.3 μm with enhanced strength, ~ 615 MPa, yet with adequate ductility (22%) and formability. |